Pan Nalin’s “Faith Connections” is not the first documentary to take a camera on a pilgrimage to the Kumbh Mela festival in India. Mr. Nalin applies an on-the-ground approach, mainly looking at holy men and lost boys at the gathering. But he lets the sprawl slacken his overlong film’s grasp and, strangely, underplays the nuances of the event’s spiritual aspects.

Described as lasting 55 days and drawing up to 100 million people last year, Kumbh Mela is awe-inspiring. The metropolis of temporary dwellings; the devotion to ritual, even at the risk of personal injury; and the groups of naked, white-powdered worshipers make for a spectacle.

Between wanderings through the masses of humanity, Mr. Nalin also dwells on individuals — particularly one sadhu, or holy man, who is delightedly raising an orphan, despite the demands of his faith, and a wisecracking, hunched runaway. Both sadhu and runaway are fascinating because we see their idiosyncratic paths against the backdrop of the crowd mentality.

Understandably, many people go missing at the festival, and Mr. Nalin keeps returning to the dramas that result. While these are part of the festival’s experience, they also divert attention from its religious underpinnings, which are probably unfamiliar to many viewers in most respects.

With one especially elegant shot of worshipers crisscrossing bridges, Mr. Nalin demonstrates his ability to conjure some of the essence of this spiritual journey. But the organic nature and hard-to-fathom scale of Kumbh Mela demand a more systematic strategy.